Background: The incidence of treated end-stage renal disease (ESRD) and the cost of the Medicare ESRD Program are rising alarmingly. Little is known about risk factors for ESRD. Health services may play a key role both as protective factors and as risk factors for kidney failure. Aims: To identify modifiable risk factors for ESRD in the general popula- tion, mainly those related to health services. To estimate relative risks (RR) and population attributable risks (PAR) for all risk factors. Hypotheses: For each risk factor, the hypothesis is that patients with ESRD are more likely to be exposed than unaffected controls. Methods: Design: population based case-control study. Population: resi- dents of Maryland, Virginia, West Virginia, and Washington D.C. aged. 20 to 65 years. Study sample: new ESRD cases (500), from the Medicare ESRD Registry; population controls (250), selected by random dialing, matched for age. Instrument: pre-tested telephone interview. Risk factors: sex; race; access to care (insurance, preventive services, provider);history of hypertension (duration, severity, control), diabetes, vascular eases,, urinary infections; use of analgesics, antibiotics, and radiocontrast media; family history; smoking; alcohol and drug use; occupation; socio-economic status. Data analysis: estimation of RR and PAR for each risk factor; univariate and multivariate; overall and stratified by underlying diagnosis. Comparison of hypertension histories of patients with "hypertensive" ESRD and those with other ESRD. Evaluation of black race after adjustment for other risk factors. Strengths: quick, low-cost and powerful design; estimation of the population impact of each risk factor (PAR); evaluation of social factors in addition to biologic processes; adequate racial mix to study the excess of ESRD in blacks; exploitation of pre-collected Medicare data; support by team with exten- sive experience in the field; feasibility established in pilot study. Limitations: Possible information bias (evaluated). Significance: This study will provide a basis for policy decisions regarding the prevention of ESRD and its treatment.